To set the record straight about agriculture and climate change, Hannah Binns asks Dr Ceris Jones, NFU climate change adviser, to dispel the most common myths.
Yes, the Earth’s climate has always changed and, during the last million years or so, the Earth’s climate has had a natural cycle of cold and warm periods.
This cycle is influenced by greenhouse gases (GHGs) and other things such as volcanic eruptions and changes in solar activity, but the latter two things alone cannot explain the changes in temperature seen during the last century.
More GHGs in the atmosphere leads to a warmer planet.
An overwhelming majority of the world’s scientists say human activities are estimated to have caused about 1degC of global warming above pre-industrial level.
The same group of scientists, the Intergovernmental Panel on Climate Change, has said climate change, including increases in frequency and intensity of extremes, has adversely impacted food security.
Farmers are already seeing the effects of this change in the UK through longer growing seasons, seemingly more frequent severe weather and new crops and new pests and diseases, such as bluetongue, appearing.
Across all sectors of our industry, ruminants emit the most greenhouse gases.
More than 50 per cent of agriculture’s emissions are methane, while more than 30 per cent are nitrous oxide and 10 per cent are CO2 emissions.
In perspective, cattle and sheep only account for 5.7 per cent of the UK’s total emissions, and 3.7 per cent if you consider soil sequestration.
New science from Oxford University suggests methane should be treated differently in carbon calculations to better reflect its impact on global temperature.
This research suggests slowly decreasing methane emissions, for example 10 per cent over 30 years, does not cause any additional warming of the planet.
However, faster reductions in methane emissions lead to cooling, which perhaps gives some people more ammunition to call for a fast reduction in livestock numbers.
Conversely, increasing methane emissions cause a lot of warming, equivalent to very large emissions of CO2, but only while those increases are happening
About 65 per cent of the UK’s farmland is best suited to growing grass if the country wants food from these areas, and this is utilised by farmers to produce protein-rich products.But this soil and pastureland is also a good store of carbon.
It is important to maintain and manage this store as many grassland farmers have done for years and such stewardship should be rewarded.
However, science tells us that eventually the amount of carbon which can be stored in soil reaches a plateau.
This means that opportunities for further significant increases of carbon in permanent grassland are probably small, but changing management, for example alleviating compaction, could lead to small amounts.
In contrast, our arable soils have lost carbon over time.
It is interesting to see some arable farmers bringing livestock back into their rotations for their soils – a real opportunity for different sectors to work together.
Plants take CO2 out of the atmosphere every day, but the carbon stored in the above-ground/green part of plants, whether arable crops or grass, is harvested and eaten in relatively quick, short cycles and does not reduce our impact on the climate.
Water footprint is another interest of consumers to measure the environmental impact of a product.
It can be broken down into three categories: n Green is water from rain stored in the roots of soils and transpired by plants.
It is estimated about 57,000 litres of water is used to produce 1kg of English lamb, of which only 0.1 per cent is blue water and 96.6 per cent is green.
About 1kg of beef takes 17,000 litres of water, consisting of 84.4 per cent green water and 0.4 per cent blue.
So, the hydrological impact of beef and sheep production in England is small, since it mainly uses green and grey water, rather than water sourced from surface or ground.
It is important to consider the water use behind the products we import, especially if they are from drought-prone countries extracting blue water for production, as it could make them more water-stressed in the future.
Animal products, in particular beef, lamb and dairy, do have higher greenhouse gas (GHG) footprints per kilo or per litre than other livestock and plant products.
People eat because of nutrients they need, so Bristol University researchers have suggested a different way of calculating emissions from livestock products which better reflects the nutritional content of the food eaten.
Including recommended dietary intakes in the calculation accounts for the higher nutritional value, allowing better comparison.
But every type of food production, even plant-based products, has some GHG and wider environmental impacts and these will be different depending on the products and where they come from.
It is difficult for farmers in the debate, especially livestock farmers, because it must feel like everyone is saying it is all their fault.
But the Intergovernmental Panel on Climate Change has said ‘balanced diets featuring plant-based foods, such as coarse grains, legumes, fruits and vegetables, and animal-sourced food produced sustainably in low GHG emission systems, present opportunities for adaptation and mitigation’.
Farmers should be proud and confident about the range of things they are doing and want to do, not only to reach net zero, but also to provide for their families, support rural economies, look after the countryside and importantly feed the nation.
There is no one solution to tackling climate change, especially not in agriculture.
The NFU recognises the important role trees and hedgerows play in achieving our net zero goal but it is vital that the right tree is planted in the right place.
Thought must be given to what is being replaced to make sure there are no significant negative impacts, both for the environment and the economy of rural communities.
We want to see trees in the wider landscape outside woodlands recognised for their carbon storage and environmental benefit.
Tree planting present challenges to tenancies which also need to be addressed.
The UK has three/four GHG calculators which are freely available for farmers.
They can be useful in helping farmers to understand where the hotspots of emissions are on farm as well as producing a footprint of the farm or its products.
But a calculator cannot capture everything that happens farm and farmers have found that there are differences between calculators.
This can be frustrating with many calling for agreement on a single calculator.
This could be possible, but would we be confident that all supply chains would recommend the same calculator?
And what about our international competitors, would they use our calculator?
As things stand, give one or two calculators a try and when you find one that helps and works for you, stick with it so you can benchmark your own performance.
An action or process of compensation for greenhouse gases made from human or industrial activity by making equivalent reductions of greenhouse gas levels elsewhere
The removal, capture and storage of carbon from the atmosphere n Carbon sink: Any process, activity or mechanism that removes carbon from the atmosphere n Climate change: Long-term changes in the Earth’s climate
An increase in the Earth’s average surface temperature from human-made greenhouse gas (GHG) emissions
Gases that trap heat from the Earth and warm the surface, such as carbon dioxide, nitrous oxide and methane
A term referring to the amount of greenhouse gas emissions caused by an individual, event, organisation, service or product, expressed as a carbon dioxide equivalent. Often also described as a carbon footprint, but using the phrase GHG footprint ensures everyone understands that all GHGs are included in the calculation
Achieving net zero means reducing global greenhouse gas emissions to a much lower level than today – and balancing the remaining emissions by reabsorbing the same amount from the atmosphere
Measurement of the amount and impact of water used to produce each of the goods and services we use
With a target of net zero carbon emissions by 2040, there is still a long way to go.
Visit the Net Zero home page to cut through the jargon and view our brand new showcase of some of the measures already having positive results on farms up and down the country.
Visit the series home page for more information